title: Randomized double-blind placebo-controlled trial of sublingual immunotherapy in children with house dust mite allergy in primary care: study design and recruitment.
abstract: BACKGROUND
  For respiratory allergic disorders in children, sublingual immunotherapy has been developed as an alternative to subcutaneous immunotherapy. Sublingual immunotherapy is more convenient, has a good safety profile and might be an attractive option for use in primary care. A randomized double-blind placebo-controlled study was designed to establish the efficacy of sublingual immunotherapy with house dust mite allergen compared to placebo treatment in 6 to 18-year-old children with allergic rhinitis and a proven house dust mite allergy in primary care. Described here are the methodology, recruitment phases, and main characteristics of the recruited children.
  
  
  METHODS
  Recruitment took place in September to December of 2005 and 2006. General practitioners (in south-west Netherlands) selected children who had ever been diagnosed with allergic rhinitis. Children and parents could respond to a postal invitation. Children who responded positively were screened by telephone using a nasal symptom score. After this screening, an inclusion visit took place during which a blood sample was taken for the RAST test.
  
  
  RESULTS
  A total of 226 general practitioners invited almost 6000 children: of these, 51% was male and 40% <12 years of age. The target sample size was 256 children; 251 patients were finally included. The most frequent reasons given for not participating were: absence or mildness of symptoms, absence of house dust mite allergy, and being allergic to grass pollen or tree pollen only. Asthma symptoms were reported by 37% of the children. Of the enrolled children, 71% was sensitized to both house dust mite and grass pollen. Roughly similar proportions of children were diagnosed as being sensitized to one, two, three or four common inhalant allergens.
  
  
  CONCLUSIONS
  Our study was designed in accordance with recent recommendations for research on establishing the efficacy of sublingual immunotherapy; 98% of the target sample size was achieved. This study is expected to provide useful information on sublingual immunotherapy with house dust mite allergen in primary care. The results on efficacy and safety are expected to be available by 2010.
  
  
  BACKGROUND
  the trial is registered as ISRCTN91141483 (Dutch Trial Register).
authors.affiliation: Department of General Practice, Erasmus MC-University Medical Center Rotterdam, Rotterdam, the Netherlands. c.debot@erasmusmc.nl
authors.forename: Cindy M A
authors.initials: CM
authors.lastname: de Bot
authors.forename: Heleen
authors.initials: H
authors.lastname: Moed
authors.forename: Marjolein Y
authors.initials: MY
authors.lastname: Berger
authors.forename: Esther
authors.initials: E
authors.lastname: Röder
authors.forename: Hans
authors.initials: H
authors.lastname: de Groot
authors.forename: Johan C
authors.initials: JC
authors.lastname: de Jongste
authors.forename: Roy Gerth
authors.initials: RG
authors.lastname: van Wijk
authors.forename: Johannes C
authors.initials: JC
authors.lastname: van der Wouden
mesh_terms: D000286:Administration, Sublingual; D000293:Adolescent; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000008:administration & dosage*; D002648:Child; D040002:Dermatophagoides pteronyssinus / Q000276:immunology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011320:Primary Health Care; D011788:Quality of Life; D012221:Rhinitis, Allergic, Perennial / Q000453:epidemiology / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D039741:Antigens, Dermatophagoides